Fig. 2. DNA binding by Hesx1/HESX1 and HESX1 mutants. EMSA with wild-type and mutant proteins binding to dimeric P3 and monomeric GBS sites. (A) HESX1(S170L) binding affinity is defective relative to wild-type HESX1. Increasing concentrations (0.9-240 nM) of purified recombinant WT HESX1 or HESX1(S170L) were added to the labelled binding sites indicated. (B) HESX1(N125S) binds DNA with at least wild-type affinity. Increasing concentrations (0.78-25 nM) of purified recombinant wt HESX1 or HESX1 (N125S) were added to the labelled P3 and monomeric GBS sites respectively. (C) Wild-type HESX1 and HESX1(S170L), but not HESX1(R160C) and HESX1(N125S), could form ternary complexes with an antibody to the amino-terminal His tag. All proteins were added at concentrations of 25 nM.